the whole idea of a ucallocb() is bad, as even access to the
metadata header would be in uncached memory. also, it tuns out
that it was never used by anyone.
The new pci code is moved to port/pci.[hc] and shared by
all ports.
Each port has its own PCI controller implementation,
providing the pcicfgrw*() functions for low level pci
config space access. The locking for pcicfgrw*() is now
done by the caller (only port/pci.c).
Device drivers now need to include "../port/pci.h" in
addition to "io.h".
The new code now checks bridge windows and membars,
while enumerating the bus, giving the pc driver a chance
to re-assign them. This is needed because some UEFI
implementations fail to assign the bars for some devices,
so we need to do it outselfs. (See pcireservemem()).
While working on this, it was discovered that the pci
code assimed the smallest I/O bar size is 16 (pcibarsize()),
which is wrong. I/O bars can be as small as 4 bytes.
Bit 1 in an I/O bar is also reserved and should be masked off,
making the port mask: port = bar & ~3;
replace machine specific userinit() by a portable
implemntation that uses kproc() to create the first
process. the initcode text is mapped using kmap(),
so there is no need for machine specific tmpmap()
functions.
initcode stack preparation should be done in init0()
where the stack is mapped and can be accessed directly.
replacing the machine specific userinit() allows some
big simplifications as sysrfork() and kproc() are now
the only callers of newproc() and we can avoid initializing
fields that we know are being initialized by these
callers.
rename autogenerated init.h and reboot.h headers.
the initcode[] and rebootcode[] blobs are now in *.i
files and hex generation was moved to portmkfile. the
machine specific mkfile only needs to specify how to
build rebootcode.out and initcode.out.
fault() now has an additional pc argument that is
used to detect fault on a non-executable segment.
that is, we check on read fault if the segment
has the SG_NOEXEC attribute and the program counter
is within faulting page.
a portable SG_NOEXEC segment attribute was added to allow
non-executable (physical) segments. which will set the
PTENOEXEC bits for putmmu().
in the future, this can be used to make non-executable
stack / bss segments.
the SG_DEVICE attribute was added to distinguish between
mmio regions and uncached memory. only matterns on arm64.
on arm, theres the issue that PTEUNCACHED would have
no bits set when using the hardware bit definitions.
this is the reason bcm, kw, teg2 and omap kernels use
arteficial PTE constants. on zynq, the XN bit was used
as a hack to give PTEUNCACHED a non-zero value and when
the bit is clear then cache attributes where added to
the pte.
to fix this, PTECACHED constant was added.
the portable mmu code in fault.c will now explicitely set
PTECACHED bits for cached memory and PTEUNCACHED for
uncached memory. that way the hardware bit definitions
can be used everywhere.
the only architecture dependence of devether was enabling interrupts,
which is now done at the end of the driver's reset() function now.
the wifi stack and dummy ethersink also go to port/.
do the IRQ2->IRQ9 hack for pc kernels in intrenabale(), so not
every caller of intrenable() has to be aware of it.
introducing the PFPU structue which allows the machine specific
code some flexibility on how to handle the FPU process state.
for example, in the pc and pc64 kernel, the FPsave structure is
arround 512 bytes. with avx512, it could grow up to 2K. instead
of embedding that into the Proc strucutre, it is more effective
to allocate it on first use of the fpu, as most processes do not
use simd or floating point in the first place. also, the FPsave
structure has special 16 byte alignment constraint, which further
favours dynamic allocation.
this gets rid of the memmoves in pc/pc64 kernels for the aligment.
there is also devproc, which is now checking if the fpsave area
is actually valid before reading it, avoiding debuggers to see
garbage data.
the Notsave structure is gone now, as it was not used on any
machine.
introduce cpushutdown() function that does the common
operation of initiating shutdown, returning once all
cpu's got the message and are about to shutdown. this
avoids duplicated code which isnt really machine specific.
automatic reboot on panic only when *debug= is not set
and the machine is a cpu server or has no display,
otherwise just hang.
there are no kernels currently that do page coloring,
so the only use of cachectl[] is flushing the icache
(on arm and ppc).
on pc64, cachectl consumes 32 bytes in each page resulting
in over 200 megabytes of overhead for 32gb of ram with 4K
pages.
this change removes cachectl[] and adds txtflush ulong
that is set to ~0 by pio() to instruct putmmu() to flush
the icache.
there is no use for "bootdisk" variable parametrization
of /boot/boot and no point for the boot section with its
boot methods in the kernel configuration anymore. so
mkboot and boot$CONF.out are gone.
move the rules for bootfs.paq creation in 9/boot/bootmkfile.
location of bootfs.proto is now in 9/boot/bootfs.proto.
our /boot/boot target is now just "boot".
this change is in preparation for amd64. the systab calling
convention was also changed to return uintptr (as segattach
returns a pointer) and the arguments are now passed as
va_list which handles amd64 arguments properly (all arguments
are passed in 64bit quantities on the stack, tho the upper
part will not be initialized when the element is smaller
than 8 bytes).
this is partial. xalloc needs to be converted in the future.
dont spam the console with qfull warnings. this makes things worse.
handle loopback packets as stated in the comment. we call etheriq()
with fromwire=1 for loopback packets so etheriq() can pass the packet
on (without copying) or free it. dont inhibit interrupts while calling
etheriq(). etheriq() can safely be called from process and interrupt
context. it is unclear what this was supposed to fix and testing didnt
seem to have any odd effects.
this simplifies the arm ports and keeps all the stuff in one place
instead of spreading it thru notify(), trap() and syscall() functions
and prevents useless fp state copying for kernel procs.
also make sure to save fp in notify while still splhi().
the kernel uses fixed area (TSTKTOP, TSTKSIZ) of the address
space to temporarily map the new stack segment for exec. for
386 and arm, this area was right below the stack segment which
has the problem that the program can map arbitrary segments
there (even readonly).
alpha and ppc dont have this problem as they map the temporary
exec stack *above* the user reachable stack segement and segattach
prevents one from mapping anything above or overlaping the stack.
lots of arch code assumes USTKTOP being the end of userspace
address space and changing this to TSTKTOP would work, but results
in lots of hard to test changes.
instead, we'r going to map the temporary stack programmatically
finding a hole in the address space where to map it. we also lift
the size limitation for arguments and allow arguments to fill
the whole new stack segement.
the TSTKTOP and TSTKSIZ are not used anymore so they where removed.
references:
http://9fans.net/archive/2013/03/203http://9fans.net/archive/2013/03/202http://9fans.net/archive/2013/03/197http://9fans.net/archive/2013/03/195http://9fans.net/archive/2013/03/181
